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Biomechanics of cervical facet dislocation
Paul C Ivancic1, Adam M Pearson, Yasuhiro Tominaga
1Biomechanics Research Laboratory, Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut 06520-8071, USA. paul.ivancic@yale.edu
Traffic Injury Prevention
|December 6, 2008
Summary
This study computed dynamic neck loads during simulated high-speed cervical facet dislocation. Findings reveal key injury mechanisms involving flexion moment, axial compression, and anterior shear forces.
Area of Science:
- Biomechanics
- Spinal Injury Research
- Trauma Mechanics
Background:
- Cervical facet dislocations are severe injuries.
- Understanding the dynamic loads is crucial for injury prevention and treatment.
Purpose of the Study:
- To compute dynamic neck loads during simulated high-speed bilateral facet dislocation.
- To investigate the injury mechanism of cervical facet dislocation.
Main Methods:
- Ten osteoligamentous functional spinal units were subjected to frontal impacts.
- Muscle forces and motion were tracked, with a mass attached to simulate head loading.
- Inverse dynamics calculated loads during simulated dislocation events.
Main Results:
- Peak loads included axial compression (233.6 N), anterior shear (73.1 N), and flexion moment (30.7 Nm).
- Peak motions involved axial separation (5.3 mm), flexion rotation (63.1°), and anterior shear (21.5 mm).
- Posterior shear force (110.3 N) occurred as facets locked.
Conclusions:
- Bilateral facet dislocation involves significant flexion moment, axial compression, and anterior shear forces.
- These loads lead to facet separation, rotation, and anterior translation.
- The study elucidates the injury mechanism of cervical facet dislocation.
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